Chlorine is the primary disinfectant for drinking water in the world. However, there is some concern over the use of chlorine compounds to disinfect drinking water. These concerns stem from the potential adverse health effects of the chemical by-products, such as chloroform, found in water as a result of their use. The EPA set a maximum contaminant level of THMs, like chloroform, in drinking water at 0.10 mg/L. But, because the benefits of pretreatment of our water supply with chlorine outweigh the risks associated with no treatment, chlorine is still used.
Despite the pretreatment of water, many people do not drink it directly out of the faucet because many impurities still remain in the water. People either purchase bottled water or purchase some type of filtration system for their homes or businesses.
There are several different types of water filters available: activated carbon filters, ion exchange units, reverse osmosis units, and distillation units.
Activated carbon filters remove/reduce many volatile organic chemicals (VOC), pesticides and herbicides, as well as chlorine, benzene, trihalomethane (THM) compounds, radon, solvents and many other chemicals found in tap water. Some activated carbon filters are moderately effective at removing some heavy metals. However, frequent filter changes are required. Following scheduled filter replacements is highly important to eliminate the possibility of channeling which reduces the contact between the contaminant and the carbon and therefore reduces efficiency, and the accumulation of bacteria in the filter.
Ion exchange units typically consists of permanent insoluble anions, kept electrically neutral by replaceable sodium cations. Zeolite is often used in ion exchange units. As the hard water flows through it, the magnesium and calcium cations in the water are drawn to the anions of the ion exchanger. Because the ion exchanger has a greater affinity for the calcium and magnesium ions than for the sodium ions, the harmless sodium ions replace the hardness ions of magnesium and calcium. In time, however, the amount of sodium ions will be depleted and the ion exchange process will cease. The ion exchange material will therefore need to be regenerated by passing high concentrations of Sodium Chloride (NaCl) solution through the ion exchange material, thereby replacing the magnesium and calcium ions with sodium ions. And, while this is helpful in softening water, it does not aid in the removal of residual chlorine.
Reverse osmosis units use a membrane that is semi-permeable, allowing pure water to pass through it, while rejecting the contaminants that are too large to pass through the tiny pores in the membrane. However, because reverse osmosis works against standard osmotic pressure, the process is generally fairly slow, producing roughly 15 gallons of purified water per day, and may require from 3 to 10 gallons of untreated water to make a single gallon of purified water. Furthermore, molecules that are molecularly smaller than water will not be blocked by the membrane. Therefore, pesticides, herbicides and chlorine will not be filtered from the water.
Distillation units require that water is boiled. However, organics such as herbicides and pesticides, with boiling points lower than 100° C. cannot be removed efficiently. It is also very expensive as distillation requires large amounts of energy and water.
The present invention is directed to an improved water filter that is enhanced with self-generated electricity, longer lasting, and more effective in the removal of chlorine and other pollutants.